The strlen() function

The strlen() function is used to return the length of a string.
Let's find the length of a string:
< ?php
echo strlen("Hello world!");
? >
The output of the code above will be:
12
The length of a string is often used in loops or other functions, when it is important to know when the string ends. (i.e. in a loop, we would want to stop the loop after the last character in the string).